This invention relates to road working equipment and, more particularly, to a method and apparatus for removing pavement from a road bed.
When resurfacing a road, it is often desirable to remove the existing pavement in order to maintain the original grade and/or recycle the pavement material in the case of asphalt. There are a number of known procedures for removing asphalt pavement, all of which require an expenditure of a great deal of time, money, and/or effort.
One procedure is to soften the asphalt pavement with a radiant heater or flame burner, and then clean off the softened asphalt in layers with the mold board of a road grader. The thickness of each layer removed in this manner is limited by the depth of the asphalt that can be softened by the radiant heater or flame burner, which is very small.
Another procedure that has been used without much success is to remove the asphalt pavement with a plurality of diamond cutting wheels arranged on a common rotating shaft. The experience has been that these cutting wheels are expensive and the operation is slow.
A third procedure is to mill off the pavement in layers with a rotating drum on which carbide tips or teeth are mounted. In order to make a deep cut in the pavement, a great deal of downward force needs to be exerted on the drum, which results in too many fine particles if the asphalt is to be recycled.
Still another procedure is to use sonic energy to cut into pavement. As described in Bodine U.S. Pat. No. 3,232,669, a sonic vibration generator is coupled to the upper end of an essentially vertical beam or bar having pavement-engaging teeth or serrations formed at its lower end. The vibration generator supplies energy to the beam at its resonant frequency, and the vibrating teeth at the lower end of the beam cut into the pavement.